January 14, 2015 at
9:25 AM

Boston has acquired left-handed pitcher Danny Rosenbaum from the Washington Nationals in exchange for catcher Dan Butler. Butler had been designated for assignment last week. Rosenbaum is not currently on the 40-man roster, giving the team additional flexibility. He appeared in only four games in 2014 before suffering an injury to the UCL in his throwing elbow that required Tommy John surgery. The news was first reported by Nick Cafardo of The Boston Globe on Twitter.

Rosenbaum, 27, was originally selected by Washington in the 22nd round of the 2009 draft. The former Xavier Musketeer moved quickly through the low minors, reaching Double-A by 2011. Following the 2012 season he was selected by Colorado in the Rule 5 draft, but failed to make the team out of spring training and was returned to the Nationals before opening day. Rosenbaum went on to have a solid but unspectacular 2013 with Triple-A Syracuse, posting a 3.87 ERA and 1.478 WHIP in 158 1/3 innings. He returned to Syracuse to begin 2014 but underwent surgery in early May, ending his season. Per Chase Hughes at CSNWashington, Rosenbaum was cleared to begin a throwing program in November.

Rosenbaum is primarily a sinkerball pitcher, generating outs with a high ground-ball rate despite middling strikeout numbers. He has been used almost exclusively as a starting pitcher throughout his minor league career. He will be eligible for minor league free agency following the 2015 season, assuming he pitches at some point.

Washington was able to take advantage of a pair of extra spots on its 40-man roster to add Butler for catching depth. His trade leaves the Red Sox with only three catchers on their own 40-man. Originally signed as an undrafted free agent out of the University of Arizona, Butler appeared in over 500 games during his time in the Red Sox organization and made his major league debut in 2014.